The point the article is trying to make wrt immigration is that when the UK leaves the EU, it will also leave the free movement of workers zone, making it harder to attract immigrants, regardless of how London feels about them.
The UK is a knowledge economy, it will always be open to skilled immigrants. Yet people actually believe that the UK will close down all immigration. It's absurd.
And I don't want to start talking about other things, such as access to social security and cross-border cooperation thereof, automatic recognition of degrees and certifications, harmonized banking makes it easy to transfer to your home country, being able to quit a job without needing to have a new one lined-up, and so on. All that is now part of the negotiations.
That's exactly the point, and something I don't think many British people realise. (I don't think Americans etc realise it either, but I don't expect them to.)
Moving to work in a different EU country requires what I'd guess is a similar amount of paperwork as moving between US states.
- Register your address with the local government (which may lead to an id card, tax registration etc) - Update your driving license, if applicable - Tell the old country you'll stop paying tax there (may lead to a tax refund)
These are the same kinds of processes as are used when a child is born, a teenager gets a first job, or an adult moves house. Nothing requires permission, nothing can be refused.
Additionally, there are agreements for things like state healthcare, pensions and out-of-work benefits.
If the UK raises barriers, then London will be less appealing for other European citizens.
This is a very crucial point that a lot of people fail to grasp. With the EU laws as backing, we moved from "this is easily granted unless you fill in the wrong paper" to "this can't be denied and you don't even have to ask." which is a complete turnaround in the power balance. Employing a person from the EU requires that I notify the relevant authorities, moving within the EU requires me to merely notify the right parties. There's no applying for a permit. Having a polish partner is much less stressful, because she can't be thrown out, no matter what, no need for a residence permit, no travel documents.
There's a tsunami of red tape heading our way both in terms of visa regulations and in many other areas where EU and UK regulations are going to start to diverge.
Unless they quickly agree on Brexit in name only we will probably move into the EU, possibly to Scotland if they become independent.
Legal aspects aside, this referendum was also a shot across the bow to foreigners. To have such a large majority expressing such a strong disdain should give pause to anyone considering immigration, because it is unpleasant and even dangerous to have neighbors who think of you like this. Seeing as Trump has made his campaign a referendum on immigration, it will be the same in the US if Trump is elected with a similar majority.
Do you understand how EU freedom of movement works? As an EU citizen I can get on a plane tomorrow, and go to any other EU country, and work there. Skills or no skills. And if I'm not happy with my job there I can quit and get another without fear of being deported. And so on...
A points-based system would be a very different proposition. There'd be far more bureaucracy involved in getting in in the first place, and then once you're in there'd potentially be issues with changing job, and with long-term residence, and with medical care, and with this, that and the other.
There is no possible way in which shutting down free movement wouldn't make the UK a less attractive destination. Of course, this is irrelevant; the UK will almost certainly have to accept free movement as part of its future EEA or EFTA member status.
This is far stronger than anything you can get via other immigration routes and such deportations of EU citizens are really rare.